Article deals with a comparative legal analyses of the concept of environmentally sustainable cities elaborated by the United Nations Environment Program (UNEP) and the UN–Habitat Program, on the one hand, and in the subregion of East Africa, wider Caribbean region and in the South-East Asian region, presented by the Association of Southeast Asian Nations (ASEAN) - on the other. The competence of the ASEAN working group on environmentally sustainable cities, the criteria of sustainability, established in the ASEAN and conditions of nomination on environmentally sustainable city title are disclosed. The problems of wastes in the Southeast Asian region are analyzed and different possible ways of their solution are suggested separately. Several examples of environmental problems settlement in different cities of different parts of the Earth are suggested. Special attention is paid to different criteria, which are used in the framework of ASEAN Environmentally Sustainable Cities Program with concern to the air, water, soil and energy supply. In connection with the latest problem the problem of alternative energy sources in ASEAN Member States is raised and the task of possible transition to alternative sources of energy of all Southeast Asia states is discussed.